Mitsubishi Electric Research Laboratories

Displaying 1-40 of 59 results

  • White Papers // Aug 2011

    Secret Key Sharing and Rateless Coding for Practical Secure Wireless Transmission

    The authors discuss a secure wireless communication scheme, focusing on designing two major components: the key generation and the coding scheme. To achieve high key matching rate, they propose a feed-forward and feed-back quantization. The proposed scheme offers 1 dB improvement over the best known schemes. They also propose a...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Jun 2011

    Experiments on Wireless Power Transfer With Metamaterials

    In this paper, the authors propose the use of metamaterials to enhance the evanescent wave coupling and improve the transfer efficiency of a wireless power transfer system based on coupled resonators. A magnetic metamaterial is designed and built for a wireless power transfer system. They show with measurement results that...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Jun 2011

    Resource Block Embedding: Towards High Throughput Broadband Multimedia Wireless Networks

    For Orthogonal Frequency-Division Multiplexing (OFDM) based wireless systems, a Resource Block (RB) in a two-dimensional time-frequency plane is defined as a data block spanned by a number of consecutive OFDM symbols over a number of consecutive sub-carriers. Traditionally, RBs contain modulation symbols for data transmission and pilot symbols for channel...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Jun 2011

    Pilot Matrix Design for Estimating Cascaded Channels in Two-Hop MIMO Amplify-and-Forward Relay Systems

    In this paper, the authors consider a two-hop Multi-Input-Multi-Output (MIMO) Amplify-and-Forward (AF) relay system consisting of a Source Node (SN), a Destination Node (DN), and a Relay Node (RN) that simply amplifies and forwards its received signal to the DN without any further processing. In this system, the overall channel...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Jun 2011

    Reduced-Rate OFDM Transmission With Statistics-Based ICI Mitigation

    In this paper, the authors develop a general reduced-rate Orthogonal Frequency Division Multiplexing (OFDM) transmission scheme for Inter-sub-Channel Interference (ICI) mitigation in a high-mobility environment. By transmit and receive pre-processing, they transform the original OFDM system into an equivalent one with fewer sub-carriers and significantly reduced ICI. A general structure...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // May 2011

    Privacy Preserving Probabilistic Inference With Hidden Markov Models

    Alice possesses a sample of private data from which she wishes to obtain some probabilistic inference. Bob possesses Hidden Markov Models (HMMs) for this purpose, but a person wants the model parameters to remain private. This paper develops a framework that enables Alice and Bob to collaboratively compute the so-called...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Apr 2011

    The Light-Path Less Traveled

    This paper extends classical object pose and relative camera motion estimation algorithms for imaging sensors sampling the scene through light-paths. Many algorithms in multi-view geometry assume that every pixel observes light traveling in a single line in space. The authors wish to relax this assumption and address various theoretical and...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Apr 2011

    Achieving Near-Exponential Diversity on Uncoded Low-Dimensional MIMO, Multi-User and Multi-Carrie Systems Without Transmitter CSI

    It is well-known that for Single-Input and Single-Output (SISO) narrow-band transmission on frequency-flat fading channels, uncoded communication with only Receiver Channel State Information (Rx-CSI) leads to extremely poor reliability performance whereas Transmitter CSI (Tx-CSI) allows them approach the reliability of an Additive White Gaussian Noise (AWGN) channel via power control....

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Mar 2011

    Capacity, MSE and Secrecy Analysis of Linear Block Precoding for Distributed Antenna Systems in Multi-User Frequency-Selective Fading Channels

    Block transmission with cyclic prefix is a promising technique to realize high-speed data rates in frequency-selective fading channels. Many popular linear precoding schemes, including Orthogonal Frequency-Division Multiplexing (OFDM), Single-Carrier (SC) block transmission, and Time-Reversal (TR), can be interpreted as such a block transmission. This paper presents a unified performance analysis...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Feb 2011

    An Information-Theoretic Analysis of Revocability and Reusability in Secure Biometrics

    Secure biometric systems are designed to allow authentication without requiring a reference biometric sample to be stored in the clear at the access control device. Instead, a template extracted from the reference biometric is stored on the device. An enrolled user can be authenticated by the template combined with a...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Jan 2011

    Performance Analysis of Joint Opportunistic Scheduling and Receiver Design for MIMO-SDMA Downlink

    In this paper, the sum-rate performance of Joint Opportunistic Scheduling and Receiver Design (JOSRD) is analyzed for multiuser Multiple-Input-Multiple Output (MIMO) Space-Division Multiple Access (SDMA) downlink systems. In particular, the authors study linear rake receivers with selective combining, maximum ratio combining and optimal combining in which signals received from all...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Dec 2010

    Location Aware Fast Handover Between WiMax and WiFi Networks

    Next generation mobile communications will rely on integrated networks consisting of multiple wireless access technologies such as WiFi, WiMAX, GSM and UMTS. With variety of access technologies, mobile users want to take diverse advantage without any disruptions when they move from one place to another. Seamless handover in between homogeneous...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Dec 2010

    Safety Message Transmission in Vehicular Communication Networks

    Emerging vehicular safety applications require low latency communications and reliable packet dissemination for life saving safety messages. Significant developments have taken place over the past few years. IEEE WAVE and ISO CALM have been developed as international standards for ITS applications. Both WAVE and CALM support multichannel operations and use...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Dec 2010

    Effect of Transmission Parameters on Efficiency and Reliability of V2V Networks

    Vehicle-to-vehicle communications is essential to create cooperative awareness amongst vehicles, improve roadway safety and roadway capacity, and reduce green house gas emissions. As vehicle density increases, the amount of cooperative awareness messages also increases, which in turn increases the amount of background interference in the wireless channel. Transmission under high...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Nov 2010

    P2Pi: A Minimal Solution for Registration of 3D Points to 3D Planes

    This paper presents a class of minimal solutions for the 3D-to-3D registration problem in which the sensor data are 3D points and the corresponding object data are 3D planes. In order to compare the 6 degrees-of-freedom transformation between the sensor and the object, the authors need at least six points...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Nov 2010

    Off-Grid Portable EV Charging Network Management With Dynamic Energy Pricing

    With emerging of Electric Vehicles (EV), Portable Charging Stations (PCSs) will play a key role to manage EV charging operations off-grid. Otherwise, charging hundreds of EVs at random locations and time instants would create major burden on a power supply network. This paper addresses an outstanding issue in PCS networks:...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Nov 2010

    Joint Carrier Frequency Offset and Channel Estimation for Uplink MIMO-OFDMA Systems Using Parallel Schmidt Rao-Blackwellized Particle Filters

    Joint Carrier Frequency Offset (CFO) and channel estimation for uplink MIMO-OFDMA systems over time-varying channels is investigated. To cope with the prohibitive computational complexity involved in estimating multiple CFOs and channels, pilot-assisted and semi-blind schemes comprised of parallel Schmidt Extended Kalman Filters (SEKFs) and Schmidt-Kalman Approximate Particle Filters (SK-APF) are...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Sep 2010

    Wireless Power Transmission Efficiency Enhancement With Metamaterials

    In this paper, a wireless power transfer system with magnetically coupled resonators is studied. The idea to use metamaterials to enhance the coupling coefficient and the transfer efficiency is proposed and analyzed. With numerical calculations of a system with and without metamaterials, the authors show that the transfer efficiency can...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Sep 2010

    Fundamental Limits and Improved Algorithms for Linea Least-Squares Wireless Position Estimation

    In this paper, theoretical lower bounds on performance of Linear Least-Squares (LLS) position estimators are obtained, and performance differences between LLS and Nonlinear Least-Squares (NLS) position estimators are quantified. In addition, two techniques are proposed in order to improve the performance of the LLS approach. First, a reference selection algorithm...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Sep 2010

    Electric Vehicles Network With Nomadic Portable Charging Stations

    A novel concept of portable charging station networks to serve Electric Vehicles is described. An optimum charging station deployment method is explained, and its performance has been simulated for single highway, two intersecting highways, and Manhattan-like grid traffic models. Outage probability and service waiting delay performances are evaluated. Impact of...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Aug 2010

    The Relay Selection and Transmission Trade-Off in Cooperative Communication Systems

    A common and practical paradigm in cooperative communication systems is the use of a dynamically selected best relay to decode and forward information from a source to a destination. Such systems use two phases a relay selection phase, in which the system uses transmission time and energy to select the...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Jul 2010

    A Modified Beacon-Enabled IEEE 802.15.4 MAC Emergency Response Applications

    IEEE 802.15.4 specification for MAC and PHY offers a standard for general purpose wireless sensor networks. The TG4e of IEEE 802.15 is currently engaged in defining a specification particularly suitable for industrial and commercial applications, which impose severe constraints of low latency and high reliability. In this paper, the authors...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Jul 2010

    Breaking the Interactive Bottleneck in Multi-Class Classification With Active Selection and Binary Feedback

    Multi-class classification schemes typically require human input in the form of precise category names or numbers for each example to be annotated - providing this can be impractical for the user when a large (and possibly unknown) number of categories are present. In this paper, the authors propose a multi-class...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Jul 2010

    Morphable Reflectance Fields for Enhancing Face Recognition

    In this paper, the authors present a novel framework to address the confounding effects of illumination variation in face recognition. By augmenting the gallery set with realistically relit images, they enhance recognition performance in a classifier-independent way. They describe a novel method for single-image relighting. Morphable Reflectance Fields (MoRF), which...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Jul 2010

    RelCom: Relational Combinatorics Features for Rapid Object Detection

    The authors present a simple yet elegant feature, RelCom, and a boosted selection method to achieve a very low complexity object detector. They generate combinations of low-level feature coefficients and apply relational operations such as margin based similarity rule over each possible pair of these combinations to construct a proposition...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Jul 2010

    Clustering Based Fractional Frequency Reuse and Fair Resource Allocation in Multi-Cell Networks

    Fractional Frequency Reuse (FFR), using different frequency reuse factors for cell center and edge regions, is able to effectively improve spectrum efficiency in multi-cell OFDMA networks. However, optimal performance is hard to achieve in practice as the efficiency of resource allocation could drop drastically due to the constraint from the...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Jul 2010

    Subcarrier Spreading for ICI Mitigation in OFDM/OFDMA Systems

    Two of the major challenges facing OFDM/OFDMA systems are their sensitivity to frequency selective fading and ICI due to CFO or Doppler shift, especially when the subcarrier spacing becomes smaller. The authors propose an OFDM transceiver design that employs frequency redundant subcarrier mapping to mitigate frequency selective fading and subcarrier...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Jul 2010

    Adaptive Probabilistic Decision-Based Energy Saving Strategy for the Next Generation Cellular Wireless Systems

    As Mobile Stations (MSs) in the next generation cellular wireless systems will more frequently operate on multiple applications, such as web browsing, VoIP, online video etc., energy saving becomes more critical and face new challenges from the Quality of Service (QoS) requirements. A special operation state, called sleep mode, is...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Jul 2010

    A Complete Characterization of an Optimal Timer Based Scheme

    Timer-based mechanisms are often used in several wireless systems to help a given (sink) node select the best helper node among many available nodes. Specifically, a node transmits a packet when its timer expires, and the timer value is a function of its local suitability metric. In practice, the best...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Jul 2010

    RPL Based Routing for Advanced Metering Infrastructure in Smart Grid

    In this paper, the authors present a routing protocol design and implementation for the Advanced Metering Infrastructure (AMI) in Smart Grid. The proposed protocol implementation is based on the framework of the IPv6 Routing Protocol for Low Power and Lossy Networks (RPL), which is proposed by IETF and currently still...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Jul 2010

    Multi-Class Batch-Mode Active Learning for Image Classification

    Accurate image classification is crucial in many robotics and surveillance applications - for example, a vision system on a robot needs to accurately recognize the objects seen by its camera. Object recognition systems typically need a large amount of training data for satisfactory performance. The problem is particularly acute when...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Jun 2010

    A Synchronization Design for UWB-Based Wireless Multimedia Systems

    Multi-Band Orthogonal Frequency-Division Multiplexing (MB-OFDM) Ultra-WideBand (UWB) technology offers large throughput, low latency and has been adopted in wireless Audio/Video (AV) network products. The complexity and power consumption, however, are still major hurdles for the technology to be widely adopted. In this paper, the authors propose a unified synchronizer design...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Jun 2010

    Multi-Antenna Analog Network Coding for Multi-Hop Wireless Networks

    This paper proposes a Minimum Mean-Square-Error Bi-directional Amplify-and-Forward (MMSEBAF) relaying protocol for multi-hop wireless networks employing multi-antenna relays. MMSEBAF is a two-phase relaying protocol which allows for two sources to exchange independent messages via a relay node equipped with multiple antennas. The latter performs a joint linear MMSE filtering of...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Jun 2010

    Differentiable Spectrum Partition for Fractional Frequency Reuse in Multi-Cell OFDMA Networks

    To mitigate Inter-Cell Interference (ICI) and achieve higher spectrum efficiency, Fractional Frequency Reuse (FFR) has been widely adopted by the next generation wireless systems, wherein different frequency reuse factors are applied to cell center and cell edge zones. In such conventional FFR, a contiguous radio spectrum is partitioned in a...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Apr 2010

    QoS Harmonization for Home Networks

    A modern home could contain a large variety of devices and all of them should be able to work together so as to bring a rich experience to the users. Quality of Service (QoS) is a critical factor for measuring user satisfaction. It represents the ability to provide different priorities...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Mar 2010

    Privacy and Security of Features Extracted From Minutiae Aggregates

    This paper describes the authors' recent analysis on the security and privacy of biometric feature vectors obtained from fingerprint minutiae. A large number of contiguous regions (cuboids) are selected at random in the minutiae space, and several new features are extracted from the minutiae inside each such cuboid. Specifically, the...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Mar 2010

    Hiding Information Inside Structured Shapes

    This paper describes a new technique for embedding a message within structured shapes. It is desired that one changes in the shape owing to the embedded message are invisible to a casual observer but detectable by a specialized decoder. The message embedding algorithm represents shape outline as a set of...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Mar 2010

    Optimized Opportunistic Multicast Scheduling (OMS) Over Wireless Cellular Networks

    Optimized Opportunistic Multicast Scheduling (OMS) is studied for cellular networks, where the problem of efficiently transmitting a common set of fountain-encoded data from a single base station to multiple users over quasi-static fading channels is examined. The proposed OMS scheme better balances the tradeoff between multiuser diversity and multicast gain...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Mar 2010

    QRD-Based Precoded MIMO-OFDM Systems With Reduced Feedback

    QR Decomposition (QRD)-based precoded MIMO-OFDM systems with reduced feedback are proposed to convert the MIMO-OFDM channel into layered subchannels. QRD-M is further combined with either Singular Value Decomposition (SVD) or Geometric Mean Decomposition (GMD) of the time-domain channel impulse response matrix. As a result, the receiver in the proposed systems...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Mar 2010

    TV Architecture Supporting Multiple 3D Services

    This paper describes changes to the television architecture to support 3D video, with emphasis on the receiver and display processor. It is expected that multiple 3D services will be available in the near future. While the current 3-D Ready televisions are able to display uncompressed stereoscopic video signals, the capabilities...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Sep 2009

    Adaptive Antenna Selection at Mobile Stations for SDMA in WiMAX Networks

    The IEEE 802.16/WiMAX standards has fully embraced multi-antenna technology and can, thus, deliver robust performance and high transmission rates. Nevertheless, due to its inherent cost concerns, a WiMAX Mobile Station (MS) should preferably contain fewer Radio Frequency (RF) chains than antenna elements. Thus, antenna selection, wherein a subset of antennas...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Dec 2009

    Relay-Coded Multi-User Cooperative Communications for Uplink LTE-Advanced 4G Systems

    A technical consensus for future LTE-advanced 4G systems is the adoption of Relay Stations (RS) for letter link performance. While study in relay systems is often carried out for individual users independently, this paper presents a new design termed as relay-based multi-user cooperative communication specifically for the uplink of 4G...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Feb 2010

    A WiFi Measurement in 802.11g Networks

    The hidden terminal problem is closely related to the Transmission Range (TX Range), Carrier Sensing Range (CS Range) and InterFerence Range (IF Range) of stations in wireless local area networks (WLAN). The TX Range is the range (With respect to the transmitting station) within which a transmitted frame can be...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // May 2011

    Privacy Preserving Probabilistic Inference With Hidden Markov Models

    Alice possesses a sample of private data from which she wishes to obtain some probabilistic inference. Bob possesses Hidden Markov Models (HMMs) for this purpose, but a person wants the model parameters to remain private. This paper develops a framework that enables Alice and Bob to collaboratively compute the so-called...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Mar 2011

    Capacity, MSE and Secrecy Analysis of Linear Block Precoding for Distributed Antenna Systems in Multi-User Frequency-Selective Fading Channels

    Block transmission with cyclic prefix is a promising technique to realize high-speed data rates in frequency-selective fading channels. Many popular linear precoding schemes, including Orthogonal Frequency-Division Multiplexing (OFDM), Single-Carrier (SC) block transmission, and Time-Reversal (TR), can be interpreted as such a block transmission. This paper presents a unified performance analysis...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Nov 2010

    P2Pi: A Minimal Solution for Registration of 3D Points to 3D Planes

    This paper presents a class of minimal solutions for the 3D-to-3D registration problem in which the sensor data are 3D points and the corresponding object data are 3D planes. In order to compare the 6 degrees-of-freedom transformation between the sensor and the object, the authors need at least six points...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Sep 2010

    Wireless Power Transmission Efficiency Enhancement With Metamaterials

    In this paper, a wireless power transfer system with magnetically coupled resonators is studied. The idea to use metamaterials to enhance the coupling coefficient and the transfer efficiency is proposed and analyzed. With numerical calculations of a system with and without metamaterials, the authors show that the transfer efficiency can...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Aug 2010

    The Relay Selection and Transmission Trade-Off in Cooperative Communication Systems

    A common and practical paradigm in cooperative communication systems is the use of a dynamically selected best relay to decode and forward information from a source to a destination. Such systems use two phases a relay selection phase, in which the system uses transmission time and energy to select the...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Jul 2010

    A Modified Beacon-Enabled IEEE 802.15.4 MAC Emergency Response Applications

    IEEE 802.15.4 specification for MAC and PHY offers a standard for general purpose wireless sensor networks. The TG4e of IEEE 802.15 is currently engaged in defining a specification particularly suitable for industrial and commercial applications, which impose severe constraints of low latency and high reliability. In this paper, the authors...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Jun 2010

    A Synchronization Design for UWB-Based Wireless Multimedia Systems

    Multi-Band Orthogonal Frequency-Division Multiplexing (MB-OFDM) Ultra-WideBand (UWB) technology offers large throughput, low latency and has been adopted in wireless Audio/Video (AV) network products. The complexity and power consumption, however, are still major hurdles for the technology to be widely adopted. In this paper, the authors propose a unified synchronizer design...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Jul 2010

    Breaking the Interactive Bottleneck in Multi-Class Classification With Active Selection and Binary Feedback

    Multi-class classification schemes typically require human input in the form of precise category names or numbers for each example to be annotated - providing this can be impractical for the user when a large (and possibly unknown) number of categories are present. In this paper, the authors propose a multi-class...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Jul 2010

    Morphable Reflectance Fields for Enhancing Face Recognition

    In this paper, the authors present a novel framework to address the confounding effects of illumination variation in face recognition. By augmenting the gallery set with realistically relit images, they enhance recognition performance in a classifier-independent way. They describe a novel method for single-image relighting. Morphable Reflectance Fields (MoRF), which...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Jul 2010

    RelCom: Relational Combinatorics Features for Rapid Object Detection

    The authors present a simple yet elegant feature, RelCom, and a boosted selection method to achieve a very low complexity object detector. They generate combinations of low-level feature coefficients and apply relational operations such as margin based similarity rule over each possible pair of these combinations to construct a proposition...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Jul 2010

    Clustering Based Fractional Frequency Reuse and Fair Resource Allocation in Multi-Cell Networks

    Fractional Frequency Reuse (FFR), using different frequency reuse factors for cell center and edge regions, is able to effectively improve spectrum efficiency in multi-cell OFDMA networks. However, optimal performance is hard to achieve in practice as the efficiency of resource allocation could drop drastically due to the constraint from the...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Jul 2010

    Subcarrier Spreading for ICI Mitigation in OFDM/OFDMA Systems

    Two of the major challenges facing OFDM/OFDMA systems are their sensitivity to frequency selective fading and ICI due to CFO or Doppler shift, especially when the subcarrier spacing becomes smaller. The authors propose an OFDM transceiver design that employs frequency redundant subcarrier mapping to mitigate frequency selective fading and subcarrier...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Jul 2010

    Adaptive Probabilistic Decision-Based Energy Saving Strategy for the Next Generation Cellular Wireless Systems

    As Mobile Stations (MSs) in the next generation cellular wireless systems will more frequently operate on multiple applications, such as web browsing, VoIP, online video etc., energy saving becomes more critical and face new challenges from the Quality of Service (QoS) requirements. A special operation state, called sleep mode, is...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Jul 2010

    A Complete Characterization of an Optimal Timer Based Scheme

    Timer-based mechanisms are often used in several wireless systems to help a given (sink) node select the best helper node among many available nodes. Specifically, a node transmits a packet when its timer expires, and the timer value is a function of its local suitability metric. In practice, the best...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Jul 2010

    RPL Based Routing for Advanced Metering Infrastructure in Smart Grid

    In this paper, the authors present a routing protocol design and implementation for the Advanced Metering Infrastructure (AMI) in Smart Grid. The proposed protocol implementation is based on the framework of the IPv6 Routing Protocol for Low Power and Lossy Networks (RPL), which is proposed by IETF and currently still...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Jul 2010

    Multi-Class Batch-Mode Active Learning for Image Classification

    Accurate image classification is crucial in many robotics and surveillance applications - for example, a vision system on a robot needs to accurately recognize the objects seen by its camera. Object recognition systems typically need a large amount of training data for satisfactory performance. The problem is particularly acute when...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Jun 2010

    Multi-Antenna Analog Network Coding for Multi-Hop Wireless Networks

    This paper proposes a Minimum Mean-Square-Error Bi-directional Amplify-and-Forward (MMSEBAF) relaying protocol for multi-hop wireless networks employing multi-antenna relays. MMSEBAF is a two-phase relaying protocol which allows for two sources to exchange independent messages via a relay node equipped with multiple antennas. The latter performs a joint linear MMSE filtering of...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Jun 2010

    Differentiable Spectrum Partition for Fractional Frequency Reuse in Multi-Cell OFDMA Networks

    To mitigate Inter-Cell Interference (ICI) and achieve higher spectrum efficiency, Fractional Frequency Reuse (FFR) has been widely adopted by the next generation wireless systems, wherein different frequency reuse factors are applied to cell center and cell edge zones. In such conventional FFR, a contiguous radio spectrum is partitioned in a...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Apr 2010

    QoS Harmonization for Home Networks

    A modern home could contain a large variety of devices and all of them should be able to work together so as to bring a rich experience to the users. Quality of Service (QoS) is a critical factor for measuring user satisfaction. It represents the ability to provide different priorities...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Mar 2010

    Privacy and Security of Features Extracted From Minutiae Aggregates

    This paper describes the authors' recent analysis on the security and privacy of biometric feature vectors obtained from fingerprint minutiae. A large number of contiguous regions (cuboids) are selected at random in the minutiae space, and several new features are extracted from the minutiae inside each such cuboid. Specifically, the...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Mar 2010

    Hiding Information Inside Structured Shapes

    This paper describes a new technique for embedding a message within structured shapes. It is desired that one changes in the shape owing to the embedded message are invisible to a casual observer but detectable by a specialized decoder. The message embedding algorithm represents shape outline as a set of...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Mar 2010

    Optimized Opportunistic Multicast Scheduling (OMS) Over Wireless Cellular Networks

    Optimized Opportunistic Multicast Scheduling (OMS) is studied for cellular networks, where the problem of efficiently transmitting a common set of fountain-encoded data from a single base station to multiple users over quasi-static fading channels is examined. The proposed OMS scheme better balances the tradeoff between multiuser diversity and multicast gain...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Mar 2010

    QRD-Based Precoded MIMO-OFDM Systems With Reduced Feedback

    QR Decomposition (QRD)-based precoded MIMO-OFDM systems with reduced feedback are proposed to convert the MIMO-OFDM channel into layered subchannels. QRD-M is further combined with either Singular Value Decomposition (SVD) or Geometric Mean Decomposition (GMD) of the time-domain channel impulse response matrix. As a result, the receiver in the proposed systems...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Feb 2010

    Alignment and Bit Extraction for Secure Fingerprint Biometrics

    Security of biometric templates stored in a system is important because a stolen template can compromise system security as well as user privacy. Therefore, a number of secure biometrics schemes have been proposed that facilitate matching of feature templates without the need for a stored biometric sample. However, most of...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Mar 2010

    TV Architecture Supporting Multiple 3D Services

    This paper describes changes to the television architecture to support 3D video, with emphasis on the receiver and display processor. It is expected that multiple 3D services will be available in the near future. While the current 3-D Ready televisions are able to display uncompressed stereoscopic video signals, the capabilities...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Dec 2009

    Performance Analysis of Beacon-Enabled IEEE 802.15.4 MAC for Emergency Response Applications

    IEEE 802.15.4 standard provides a viable MAC and PHY specification for wireless sensor networks. Performance evaluation of these networks has been reported in literature. Previous works focus largely on analyzing the CSMA/CA traffic and frame delay due to Guaranteed Time Slots (GTS) allocations. In this paper, the authors propose a...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Dec 2009

    Leveraging Reliable Bits: ECC Design Consideration for Practical Secure Biometric Systems

    It is well-known that a biometric fuzzy vault can be constructed by applying an Error Correcting Code (ECC) to a biometric signal. This is attractive because authentication only requires the check bits of the ECC to be stored on the access control device, whereas the personal biometric traits need not...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Dec 2009

    Multi-User Cooperative Communications With Relay-Coding for Uplink IMT-Advanced 4G Systems

    Adoption of relay stations has been commonly accepted as a key technique for future IMT advanced 4G systems to improve the link performance. While study in relay systems is often carried out for individual users independently, in this paper, the authors present a design termed as relay based multi-user cooperative...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Dec 2009

    A New Coupling Channel Estimator for Cross-Talk Cancellation at Wireless Relay Stations

    In this paper, the authors are concerned with cross-talk interference from the transmit to the receive antenna of a wireless Channel-Reuse-Relay-Station (CRRS) that forwards signals over the same channel as it receives signals. By estimating the coupling channel from the transmit to the receive antenna, the proposed scheme performs cross-talk...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Dec 2009

    Opportunistic Cell Edge Selection in Multi-Cell OFDMA Networks

    The authors propose an intercell downlink Orthogonal Frequency Division Multiple Access (OFDMA) scheduling technique in a sectorized cellular network. Adjacent sectors from neighboring cells form a cluster and each OFDMA resource block is allocated to the rate-maximizing sector. Compared to a cellular network that uses conventional Fractional Frequency Reuse (FFR)...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Dec 2009

    Unified Analysis of Linear Block Precoding for Distributed Antenna Systems

    Block transmission with cyclic prefix is a promising technique to realize high-speed data rates in frequency selective fading channels. Many popular linear precoding schemes, including Orthogonal Frequency-Division Multiplexing (OFDM), Single-Carrier (SC) block transmission, and Time-Reversal (TR), can be interpreted as such a block transmission. This paper presents a unified performance...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Dec 2009

    Medium Access Control Signaling for Reliable Spectrum Agile Radios

    The authors address the problem of collaborative sensing in cognitive radios. In a cognitive radio network, all the nodes may sense the spectrum simultaneously. They should then exchange their sensing results in order to improve the reliability of the detection. This exchange of information has to be done efficiently to...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Dec 2009

    Error Control Strategies for WiMAX Multi-Hop Relay Networks

    Next generation wireless system such as advanced WiMAX (i.e. IEEE802.16m) and LTE advanced will fully embrace multi-hop relay architecture. The conventional Automatic Repeat reQuest (ARQ) and the more recent Hybrid ARQ (HARQ) are two simple yet highly effective error control techniques designed for single hop system. Nevertheless, extending them in...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Dec 2009

    Secure Distortion Computation Among Untrusting Parties Using Homomorphic Encryption

    The process of comparing two signals to determine whether they are similar or different is a key operation in numerous electrical engineering systems. For instance, in image processing, one may be interested in determining whether a compressed image has been reconstructed to within a specified mean squared error tolerance. In...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Dec 2009

    Object Detection Via Boosted Deformable Features

    It is a common practice to model an object for detection tasks as a boosted ensemble of many models built on features of the object. In this paper, features are defined as subregions with fixed relative locations and extents with respect to the object's image window. The authors introduce using...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Dec 2009

    Codebook-Based Quantized MIMO Feedback for Closed-Loop Transmit Precoding

    Advanced quantization schemes are proposed for closed-loop transmits precoding over correlated Multiple-Input Multiple-Output (MIMO) channels in this work. Unlike the conventional schemes that directly quantize the MIMO channel covariance matrix and feed back each quantized matrix element, the proposed schemes quantize the channel covariance matrix by exploiting the common rank-one...

    Provided By Mitsubishi Electric Research Laboratories

  • White Papers // Dec 2009

    Parametric Compression of Rank-1 Analog Feedback in MIMO-OFDM

    The authors consider the problem of Channel State Information (CSI) transmission on a fast feedback link for a Multiuser-MIMO OFDM system. They compare codebook based feedback with analog based feedback and propose a new compressed analog feedback suitable for correlated antennas that provides excellent tradeoff between uplink overhead and downlink...

    Provided By Mitsubishi Electric Research Laboratories